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` A. W. ROSE.

v ELECTRIC TELEPHONY. l No. 252,141.-Y Y llatenfd' 10,1882? l VI 11A/'LKN ES al; N

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UNITED STATES y ALLEN w. EosE, E NEW YORK, N. Y.

PATENT OFFICE.I

,ASSIGNOR TO CHARLES A. OHEEVER,

V ELECTRIC TELEPHONY.

SPECIFICATION forming part `of Letters Patent No. 252,141, dated January 10, 1882.l

Application tiled October 26, 1880. (No modeld To all whom tt may concern:

Beit known that I, ALLEN W. ROSE, a citizen of the Dominion of Canada, residing in the city, county, and State of'New York, have invented certain new and useful Improvements in 'Iransmitting-Telephones, ot' which the fol-- lowing is a speciication..

My improvement relates to that class of transmitting-telephones in which magnetic filro ings constitute a portion of a galvanic circuit and are held suspended by magnetism in a magnetic field therein. Such apparatus and its mode ot' operation constitute the subjectmatter of other applications tiled by me simultaneouslywith this. My present claims are therefore limited to the specific combinations and organization of devices set forth at the end ot' this specification. In the accompanying drawings, Figures 1, zo 2, and 3 respectively represent vertical Iransverse sections through different modifications of my apparatus. y

In Fig. 1 a case, C, is shown as provided with a guideway, e, in which is secured the end ot a magnet, e, curved so as to form a handle for y the instrument. Metallic filings F, in a loose condition, are interposed between the end of this magnet and a plunger, P, which must be a conductor of electricity, and is preferably of 3o magnetic material, which plunger is capable of moving freely in the gnideway, and issecured to a diaphragm, D, connected to acasing through the interposition of' buffers or springs bywhieh allow it to yield as occasion requires. One wire of an ordinary galvanic circuit is connected with this plunger, and the other with the magnet e, the circuit passing through them and through the filings. Under this organization sound-waves impinging upon the dia- 4o phragm vibrate the plunger and correlatively change the relation ofthe filings suspended in the magnetic eld between the plunger and magnet, thus producing corresponding variations in the circuit or strength of the current 45 iiowing therethrough. -These filings may be in the form of coarse powder; but I prefer to use themin the form ot' slivers or iilings of a length three or four times greater than their width or thickness. Various metals susceptible to magnetic or inductive actionsuch as 5o iron, steel, aluminium, cobalt, ornickel-may be used for such filings; but l prefer the lastnamed metal as being less liable to oxidation from moisture.

The instrument shown in Fig. 2 is similar t0 55 that shown in Fig. l, withthe exception that the. diaphragm istrigidly secured to the casing and the plunger is sustained by an elastic support, D., (which may be either an arm or spring or a second diaphragm,) the buffer or spring 6o bbein g interposed between the diaphragm and plunger instead of between the-diaphragm and casing, as in the other instance. f

In Fig.3 another modification is shown similar to the apparatus shown in Fig. 1, with the except-ion that the conductors terminate in pointed poles, the filings being suspended between them.

A mixture of filings of dissimilar magnetic metals or of powder and filings of similar or 7o dissimilar magnetic metals maybe used ini stead of lings of homogeneous metal, if preferred. Electro-magnets may also be used, if desired.

I claim herein as of my own inventionl. rlhe combination, substantially as herein set forth, of a case, a magnet secured therein,

a diaphragm, a conductor of electricity vibrating with the diaphragm, and magnetic filings in a loose state interposed in a magnetic fieldv8o V between the magnet and conductor.

2. Ihe combination, substantially as herein set forth, of atelephone-case, a guideway therein, a magnet and diaphragm connected'with the case, a conductor of electricity movable in 8 5 the guideway and vibrating with the diaphragm, magnetic tilings interposed in a magnetic teld between the magnet and conductor, yielding connectionssupporting the conductor, anda spring or yielding connection interposed 9o between the conductor and the diaphragm.

In testimony whereof' I have hereunto subscribed my name this 22d day ot October, A.

- A. W. ROSE.

Witnesses:

W.4 L. CANDEE, 4 E. C. DAVIDSON. 

